How to expand my camera view?
Wrapping up comments section with additional gifs.

Moving camera:



You can move Camera in many ways.


Grab it with G.
Fly with it Shift+F.
Or just Lock Camera to View and move around like in Viewport.


In example above I've locked camera and expanded its view along viewport.

Change Focal Length:



Second option is Focal Length under Camera tab. This one seems to be solution for you as basically it will show you more without zooming in or out. Note that it will distort objects appearance. Lower values = more distortion.

After lowering value you will need to move camera towards objects.